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Americanmachinist 2170 Imts0100png00000002794
Americanmachinist 2170 Imts0100png00000002794
Americanmachinist 2170 Imts0100png00000002794
Americanmachinist 2170 Imts0100png00000002794

60 years of challenge and change

Aug. 1, 1998
The postwar boom of the 1940s and 50s fueled growth in the machine-tool business and hastened the pace of technological advances.

The postwar boom of the 1940s and 50s fueled growth in the machine-tool business and hastened the pace of technological advances.

World War II changed the machine-tool industry in the U.S. The need to produce weaponry and vehicles spurred the development of new technologies that could cut, shape, and form metal faster, with greater precision and at lower cost. The war also changed the face of the workforce. While men fought on the battlefront, women filled the millions of civilian and defense positions created as the U.S. shifted to wartime production. In 1942, a poster of "Rosie the Riveter" helped recruit women to work in factories and shipyards.

During the 1940s, Giddings & Lewis significantly expanded its parent plant in Fond du Lac, Wis., at the request of the U.S. Government.

Warplanes were produced at Birmingham's Castle Bromwich Airdrome, only a few hundred yards from the plant of Cincinnati Milling Machines Ltd. Despite many air raids, the plant was never damaged.

The past six decades have been more tumultuous for the U.S. machine-tool industry than any comparable period in its 200+ year history. The need for arms, munitions, and the tools of war have frequently stimulated the creative juices of machine designers. The American love affair with the automobile—and all forms of transportation, for that matter— has also been responsible for constant machine and production innovation.

But the two distinguishing characteristics of the last 60 years that have been most responsible for shaping the industry have been the globalization of marketing and the emergence of microelectronics. Most successful manufacturers have had to carve a marketing niche for themselves in the context of a sophisticated, worldwide marketplace.

The following pages will briefly outline how some successful machine-tool manufacturers, tool producers, and machine-control experts have met the challenge. Most, but not all, were around before World War II, but all had to cope with pressures, dilemmas, and opportunities of the current era.

In 1940, just before WWII, only 28% of the machine tools in use were less than 10 years old. Five years later that figure had gone to 62%— the greatest change ever recorded in such a short period in any developed country for which data exist.

Between those two simple figures lay the production miracle that made World War II a different kind of war from its predecessor and that was responsible for the outcome of that war. There can be no doubt that, without this production miracle, the war would have had different victors.

The war seemed to change everything. Traditional markets had either vanished, or they had changed radically. New technologies, spawned by defense needs, offered manufacturers the opportunity to build machines that could cut, shape, and form metal faster, with greater precision and at lower cost. Many companies not taking advantage of emerging technologies soon found their products lacking the features and capabilities demanded by the metalworking world.

Immediately after the war, many industries, including many machine-tool manufacturers, found themselves with excess capacity and workforce. BUSINESS WEEK magazine reported that about 10% of wartime companies went out of business between 1945 and 1948.

Forward-thinking companies developed strategies for meeting the challenges of the postwar world and for taking advantage of the opportunities. Some expanded machinery product lines, others looked to emerging offshore markets, while still others investigated entering new markets associated with metalworking. Many companies adopted one or more of these strategies to create a future for themselves in the postwar world. Diversification, in an effort to offset the unsettling cycles typical of the machine-tool industry, became an almost universal survival tactic.

In the early 1950s, the Korean War provided yet another military boost to the machine-tool industry. However, a basic change in the nation's defense posture was heralded by the establishment of the National Production Authority. Defense preparedness and production would no longer be considered as separate from peacetime production but would be a permanent part of the nation's over-all economic policy.

Immediately after World War II, European and Japanese competition was virtually non-existent and U.S. machine-tool builders reaped the benefits. But this would change. During the 1980s the industry, in the midst of an unexpectedly deep recession, faced intense competition, particularly from Japanese machine builders. A very strong U.S. dollar also hampered export sales. From 1981 to 1983, members of the National Machine Tool Builders Association reported a drop of 66% in shipments of U.S.-built metalcutting machines.

As the wounds of war healed, overseas markets began to develop and flourish. On the other hand, offshore machine builders viewed the U.S. as an attractive market. By the late 1960s, a "one world, one market" philosophy was becoming more common. Many companies, in an effort to "fish where the fish are biting," established international operations to serve local users. In an effort to expand product and technology offerings, manufacturers frequently entered into strategic part-nerships which might include marketing agreements, equity investments, joint ventures, acquisitions, and technology exchanges.

Tool technology
In 1928, a new German cutting-tool material—a combination of tungsten carbide and cobalt—was developed by the Krupp Works in Germany. Here was a material that was to have lasting impact on manufacturing techniques and on machine-tool design.

Carbide cutting tips were a major advance over the high-speed-steel tooling predominantly in use at the outbreak of the war. In the form of indexable "throwaway" inserts, they provided the economy of multiple cutting edges and low-cost replaceability, along with capabilities for greatly increased metal-removal rates and tool life. Still, the full potential of the new carbide cutting tools could not be immediately realized, since their performance capabilities generally exceeded those of the manually controlled, and less than fully rigid, machine tools then available. Thus, most of the cutting tools used for milling, turning, boring, and drilling in the metalworking industries during the war years continued to be of the single-piece, high-speed-steel design.

Not until the introduction of NC (numerically controlled) lathes and machining centers in the 1970s did a true market present itself for the further development of indexable cemented carbide inserts. The new NC machine tools were both faster and more rigid than their predecessors, enabling the carbide inserts to realize much more of their potential for higher cutting speeds and metal-removal rates.

With expanded opportunity, the cutting-tool industry redoubled its pace of product development. New carbide grades were introduced that more closely matched the work material to be machined. Insert shapes and cutting-edge angles were refined to better suit particular types of machining. In time, mechanical chip breakers came to be replaced by complex chip-groove forms molded into the insert itself.

Thanks to rapid advances in both indexable inserts and machine tools, it wasn't long before machining operations could be completed at least three times as fast as they could during the war years with high-speed-steel tools. However, this posed yet another challenge. As machining speed, feed, and cutting depth increase, more heat is generated at the contact face between the insert and the workpiece.

In time, it became necessary for cemented carbide inserts to resist deformation at working temperatures above 1,000°C (1,832°F). To that end, individual and combined coatings of titanium nitride, titanium carbide, aluminum oxide, and other compounds were developed to enhance insert edge strength, hardness, and thermal stability, as well as a variety of other performance properties.

The development of inserts capable of cutting hardened ferrous materials and lighter materials, such as aluminum, are among many other significant advances since the war years. PCBN (polycrystalline cubic boron nitride) and PCD (polycrystalline diamond) inserts provide tooling to machine these materials with high productivity and cost-effectiveness.

Electronic control
The development of electronics technology and the microprocessor are among the most significant developments to impact the machine-tool industry. The growing use of electronics throughout industry altered the needs of machine-tool users as more companies focused on lower volume runs, higher quality, and more flexible, automated changeover systems.

In turn, electronics gave machine builders the ability to meet these needs.

Numerical control of machine tools started in the 1950s with work at MIT funded by the U. S. Air Force. The first commercial production-based NC unit was built by Bendix Corp. in 1954 for machine tools introduced in 1955. Integrated circuits (ICs), introduced in the mid-1960s, resulted in a 90% reduction in the number of components, as well as an 80% reduction in writing.

Another significant development at this time was the development of direct numerical control— DNC—where an NC machine is controlled by a computer. DNC paved the way for the first flexible manufacturing system (FMS). Such systems can produce a variety of components in random order and can easily adapt to varying volumes and mixes.

The development of minicomputers in the 1970s led to computer numerical control—CNC—which minimized the need for hard-wiring by incorporating a computer in the machine control. The advent of the microprocessor in the late 1970s brought even greater miniaturization of controls with increased memory and faster processing at lower cost.